Chatbots and conversational agents have recently seen major developments in many domains, including education. In foreign language learning, dialogue-based computer-assisted language learning (CALL) applications allow a learner to practice a foreign language by having a conversation with a computer, be it orally or in writing. I will first present the results of our multilevel meta-analysis on the effectiveness of dialogue-based CALL for second language acquisition, including how exploratory moderator analyses give directions for the design of future conversational applications.
Subsequently, I will present the methodology and preliminary results from a randomised controlled study on the effects of LanguageHero, a dialogue-based CALL game developed by the Leuven-based startup Linguineo. The study measured the effects of three sessions of practice with the game on fluency and vocabulary development in 11 class groups of elementary learners of French across 4 Flemish schools (N = 215 participants). More specifically, we measured how practice with the chatbot affected spoken fluency in a computer-delivered interview, and how the in-game written fluency could be related to it. We also compared two distinct versions of the game (dialogue system dynamic interaction vs. dialogue completion activity) to establish whether the level of interactivity and spontaneity of the writing activity affected the learning outcomes.